Instant Shutter Fix 8 speed

[Nitrousbird]

18 minutes ago, Black02Silverado said:

GM wouldn't be interested because it would cost them more money.

Except they got in bed with Mobil for the answer, which this might shock you, also costs them money.  So how does Mobil not cost them more money but Amsoil does?  Please explain.

[Black02Silverado]

15 minutes ago, Nitrousbird said:

Except they got in bed with Mobil for the answer, which this might shock you, also costs them money.  So how does Mobil not cost them more money but Amsoil does?  Please explain.

I can't answer that since I don't know the answer.  It is my understanding that GM sells Mobil because they gave them the best deal so that it can be sold at all GM dealerships. So Mobil is making a ton of money that they would not have otherwise. So if it did cost GM then it wouldn't be much since Mobil would be selling that much more. Especially for vehicles out of warranty that GM charges to fix.  Mobil is giving GM a major break on cost.  Going with a completely new vendor would be expensive.  Not to mention GM would have to figure out how to break the contract with Mobil to be able to go with a new vendors fluid.

[flyingfool]

OK being that  the Shudder is caused by the TCC and another trans parameter like allowable slip rpm.  I just completed a TCC disabled tune for my 6l80 via Richard Wardell YT vid, and man this was the main issue on these transmissions. i can say if GM is doing the same lock up patterns on the 8 speeds and 10 speeds. this will cure 80% of your problems.

I am astounded at how much better the truck drives now!! 

 

with tcc is disabled 1-4th gear, my sudden braking to a complete stop has improved and the truck feels like more rear brake bias. i love it! there is less feeling of the engine pushing durring decel. GOOD Stuff. i recommend you guys void the warrantee and extend the durability with this mod

 

 

Edited January 3, 2021 by flyingfool

[flyingfool]

just drove 100 mile on the tune, and wow! no more clunking sounds in stop and go traffic and she pulls thru the revs better with the non locked converter in 1-4th

 

 

Edited January 3, 2021 by flyingfool

[Srode1]

On 12/31/2019 at 4:33 PM, newdude said:

No.  Have the latest fluid put in it per GM's procedure.  We've done many and none have come back with a shudder. 

do you have the latest fluid part number by chance?  Mines back to doing the same old, and may have an independent shop do it unless there's something unique about the GM procedure you see only a dealer would be able to do?

[Black02Silverado]

2 hours ago, Srode1 said:

do you have the latest fluid part number by chance?  Mines back to doing the same old, and may have an independent shop do it unless there's something unique about the GM procedure you see only a dealer would be able to do?

Just curious as to how many miles are on your truck?  Would you be interested in using AMSOIL's ATF?  If so PM me your address and I can get you a total cost delivered to your door. 

[halld59]

I have gone through 3 transmissions and 2 torque converters and I still have the shudder problem and this is just on my 2015 Silverado Z-71 6.2 with 182,342 miles. The dealer is kind enough to replace under warranty. I also have a 2018 Silverado Z-71 6.2  8spd that has the same shudder. Fluid has been changed and next step is torque converter.

[Srode1]

16 hours ago, halld59 said:

I have gone through 3 transmissions and 2 torque converters and I still have the shudder problem and this is just on my 2015 Silverado Z-71 6.2 with 182,342 miles. The dealer is kind enough to replace under warranty. I also have a 2018 Silverado Z-71 6.2  8spd that has the same shudder. Fluid has been changed and next step is torque converter.

I have 80,000 on my '15 LTZ 6.2 and the shudder is back.  After fluid change/flush (done 3 times now on GMs dime).  It seems to be worse in warmer weather, was doing it last Fall and disappeared on it's own over the Winter and is now back.  I'm going to check some local shops (not dealers) to see what they have to flush the system like a dealer would and what fluid they would use.  I could do it myself but have too many other irons in the fire to mess with it right now.  Sure is disappointing GM hasn't addressed this - I would be hard pressed to buy another truck from them at this point, certainly not without a change that I can see for long enough doesn't have shifting problems.  Having friends / family along for a ride in this thing is embarrassing at times.  What a mess

[Ge0rge]

When everyone refers to shudder, what exactly do u mean? My truck will sometimes shake inside, possibly called shutter, and the console will shake back and forth. At 75k or so the trans made a clanging sound while driving like the converter had rocks in it. Dealer changed out the fluid and that noise disappeared but I always had the shake like an out of balance driveshaft or something. Local mechanic said he would change trans and converter. I am unsure what to say...

[Srode1]

14 hours ago, Ge0rge said:

When everyone refers to shudder, what exactly do u mean? My truck will sometimes shake inside, possibly called shutter, and the console will shake back and forth. At 75k or so the trans made a clanging sound while driving like the converter had rocks in it. Dealer changed out the fluid and that noise disappeared but I always had the shake like an out of balance driveshaft or something. Local mechanic said he would change trans and converter. I am unsure what to say...

The Shudder feels like you are driving over rumble strips, a fluid change including flush of torque converter should fix it for a while.  Changing the transmission and converter will not do anything any more lasting than the fluid change/flush - it's a design problem.  

[Loranger Honey]

I used Lubeguard and then a Motorcraft friction modifier as suggested by my transmission shop. The shudder was gone after the Motorcraft additive but is back.

The GM service guys cannot tell me if the new part number for the torque converter is a redesign or not. They just don't seem to care.

An after market billet converter is going to be expensive. The OEM converters are to light to take the heat.

I may sell my truck. Been a GM guy since the 80's. 

I have a '16 LTZ Z71 with 114k miles on it. Leaking AC, replaced fuel pump, transmissions been out and had converter replaced. The dealership burned up my started changing the converter and lies and said "it happens". Not if you disconnect battery.